Mix together ingredients for batter.  After you make the batter, let rest for at least 20 minutes before frying. The result will have a far better texture.

Dust the sliced watermelon in the cornstarch before dipping into the batter.

Deep-fry the watermelon until golden brown.

Set to the side to cool, then deep-fry it again to crisp up.

To make sauce, heat soybean oil in a hot wok and add garlic, ginger and hot sauce. Stir for a couple of seconds. Add balance of the ingredients. Bring to a boil. Add dissolved cornstarch to thicken sauce.

Put the golden watermelon in and coat with the sauce.

Serve.

Source:

Watermelon.org